Пару слов об ООС -
Traditionally, designers increased feedback to make a larger portion of the output signal
control the amplifiers response. Simply applying more
feedback was not the answer. In fact, as one kind of distortion went down, other parameters
would be adversely affected, leading to an overall degradation of sound quality.
Other conventional design approach of eliminating feedback completely was not
the answer either, because this would cause high distortion levels, and as a result would
produce a “woolly” sound.
The answer to the dilemma was found in a novel approach to feedback theory.
Feedback concept that allowed local feedback to be applied around individual
stages of the amplifier circuit. This approach allowed us to avoid the sonic disadvantages
of overall feedback from output to input. The concept was further developed to reduce
phase- and interphase distortion between stages of the amplifier as well. Good practice is to
concentrate the loop feedback on the stages of the amplifier where it resulted in audible
improvement.
Stability margins were also expanded because feedback no longer affected the frequency
response. The use of this concept of individual gain blocks - complex in design but simple
in function - allowed to reduce distortion to minute values
An approach like this will
prevent Transient Inter modulation Distortion (TIM) and Slewing Induced Distortion (SID),
eliminating the need for an extremely wide bandwidth.
taken from AES files